Vegetable residual flows have significant potential value in terms of functional ingredients that can be used in food or pharmaceutical applications. Onion and carrot residues in the Netherlands, Belgium and the west of Germany, for example, represent some ten million euros worth of flavonoids, an anti-oxidant. Scientists from Wageningen UR Food & Biobased Research have calculated the potential value of functional ingredients in the total vegetable residual flow in this region for the first time.

Carrots, onions, cabbage and tomato

The production, trade and processing of vegetables in the research area (the Netherlands, Belgium and the west of Germany) results in a residual flow of 860 kilotons a year, the equivalent of no less than 12.8% of the total vegetable production. Carrots are the main ingredient of the residual flow at 37%, followed by onions (27%), white cabbage (8%) and tomato (8%). In addition to flavonoids, the vegetable residue also contains other valuable ingredients such as vitamins, minerals, fibres, carotenes and amino acids.“Our analysis shows that the potential for reusing ingredients from residual flows is considerable,” says Martijntje Vollebregt, scientist at Food & Biobased Research. “It is, in fact, far larger than we initially expected.” Vollebregt worked with project partners in the Infinity platform to map out the high-quality processing options of vegetable residual flows.

Mild extraction

Cashing in on the value of the ingredients requires extraction from the residual flows in the desired quality. The first fruits of the technological research, carried out by Infinity partner TOP BV, are promising. “We have already achieved good results with beta-carotene from carrots at the laboratory and pilot scale,” Eral Osmanoglou, business developer at TOP BV explains. “We used mild extraction methods that preserve the quality of the ingredient and consume little energy.” TOP BV will upscale the tests in the coming months to make the process commercially viable.

Optimal locations for reprocessing

Logistical studies by Food & Biobased Research show that, within the research area, one processing location per product or product group is the most profitable as transport costs are low compared to the construction costs of a processing plant. The following locations are logistically the most ideal for reprocessing: Helmond in the province of Brabant for carrots, Mijdrecht for onions, Woudrichem for tomato, capsicum and aubergine, and Ottenstein in Germany for all cabbage varieties. Additional economies of scale can be achieved with a plant that can process residual flows from multiple vegetables.

More information

Infinity is a public-private partnership aimed at studying the high-quality processing of vegetable residual flows into ingredients for food and functional or pharmaceutical applications. Project partners are Wageningen UR Food & Biobased Research, TOP BV, Van Rijsingen Groep, Bodec and Bakers Basket. Infinity is financially supported by the Dutch Ministry of Economic Affairs.